What does the Saunier Duval E01 fault code mean?

Your boiler has tried to ignite but failed to detect a flame, meaning your heating and hot water will not work.

How much does it cost to fix Saunier Duval error code E01?

Typical repair cost for the Saunier Duval E01 fault is £100-350 including labour.

Check that your gas emergency control valve is in the 'on' position

Faulty ignition (flame not detected)

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Almost always a stuck diverter valve on combis.

Lockout fault with a reset-needed pattern.

Older boilers — thermocouple, draught, gas supply.